"push()" method returns the length of array instead of array (JavaScript) [duplicate]

Question

I want to make a new array by adding an element to an existing array by "push()" method.

This is the existing array:

let arr = [{label: 1, value: 1}, {label: 2, value: 2}];

This is the element I want to add to the existing array:

{label: 3, value: 3}

So this is the full code with "push()" method:

let arr = [{label: 1, value: 1}, {label: 2, value: 2}];

let newArr = arr.push({label: 3, value: 3});

console.log(newArr); // 3

But push() method returns the length of the new array which is "3" to "newArr" variable. However, what I really want is the actual new array instead of its length for "newArr" variable.

Are there any ways to get the actual new array for "newArr" variable?

Answer 1

With push you are actually mutating the original array. Immutable array extending is only available in ES2015+ (supported by all current, major browsers). You can use the spread operator ...:

const original = [1, 2];
const next = [...original, 3];
console.log(next); // [1, 2, 3]

Also new is a reserved keyword and can't be used as an identifier.